1. Field of the Technology
The present technology relates to a semiconductor laser apparatus for recording/reproducing information onto/from an information recording medium, such as an optical disc or the like, and an optical pickup apparatus using the same.
2. Description of the Related Art
A conventional optical pickup apparatus using the above-described type of semiconductor laser apparatus will be described.
FIG. 4A is a side view showing an outline structure of the conventional optical pickup apparatus. FIG. 4B is a front view showing a circumferential portion of a base portion of a semiconductor laser apparatus used in the conventional optical pickup apparatus.
As shown in FIG. 4A, the conventional optical pickup apparatus 20 has a semiconductor laser apparatus 18 in which parts, such as a semiconductor laser device (LD) 12, a monitor submount 13 and the like, are provided on a base 11; a reflection mirror 14; an objective lens 15; and a housing (not shown) which accommodates and fixes these components with a predetermined positional relationship among them.
As shown in FIG. 4B, a circumferential portion of the base 11 has two straight portions 11b which are parallel to each other and are disposed at upper and lower positions in the front view, and two arc portions 11c which are disposed at left- and right-hand positions in the front view and connect the straight portions 11b. The arc portions 11c are engaged with the housing (not shown) of the optical pickup apparatus 20, and are used to rotate the base 11 so as to adjust a site to be irradiated with the laser light. The straight portion 11b is not usually engaged with the housing, i.e., is not in contact with the housing. When the base 11 is engaged with the housing, the two straight portions 11b are arranged vertically, i.e., one of them is disposed at a higher position than that of the other.
Further, the reflection mirror 14, the objective lens 15 and an actuator (not shown) integrated with the objective lens 15 are fixed to the housing with a predetermined positional relationship among them.
In the semiconductor laser apparatus 18, the semiconductor laser device (LD) 12 is mounted on the monitor submount 13. Also, the monitor submount 13, a signal photodetector (not shown), a hologram device and the like are provided on a major surface 11a of the base 11.
In the optical pickup apparatus 20, laser light emitted from the semiconductor laser device 12 is reflected from the reflection mirror 14. Light whose traveling direction has been changed is transmitted via the objective lens 15 to an information recording surface of an optical disc 16.
In the optical pickup apparatus 20, the base 11 is fixed to the housing so that the straight portions 11b are vertically arranged, and laser light emitted from the semiconductor laser device 12 which travels in a direction parallel to the information recording surface of the optical disc 16 falls on the reflection mirror 14.
In order to make the optical pickup apparatus 20 thinner, the semiconductor laser apparatus 18 may be attached to an upper portion of the housing with a predetermined angle with respect to the housing, as shown in FIG. 5 (e.g., see, Japanese Patent No. 2626106).
FIG. 5 shows an optical pickup apparatus 20A in which the semiconductor laser apparatus 18 is attached to an upper portion of the housing in a tilted manner (a predetermined angle with respect to the housing). The lower edge of the base 11 (the lower straight portion 11b) is positioned higher than the lower edge of the reflection mirror 14 (higher than a phantom line L of FIG. 4). Thus, the lower edge of the base 11 does not project downward from the lower edge of the reflection mirror 14, resulting in the thinner optical pickup apparatus 20A.